// SPDX-License-Identifier: GPL-2.0
/*
 *    Copyright IBM Corp. 2002
 *    Author(s): Cornelia Huck (cornelia.huck@de.ibm.com)
 *               Martin Schwidefsky (schwidefsky@de.ibm.com)
 *
 * Status accumulation and basic sense functions.
 */

#include <linux/module.h>
#include <linux/init.h>

#include <asm/ccwdev.h>
#include <asm/cio.h>

#include "cio.h"
#include "cio_debug.h"
#include "css.h"
#include "device.h"
#include "ioasm.h"
#include "io_sch.h"

/*
 * Check for any kind of channel or interface control check but don't
 * issue the message for the console device
 */
static void
ccw_device_msg_control_check(struct ccw_device *cdev, struct irb *irb)
{
        struct subchannel *sch = to_subchannel(cdev->dev.parent);
        char dbf_text[15];

        if (!scsw_is_valid_cstat(&irb->scsw) ||
            !(scsw_cstat(&irb->scsw) & (SCHN_STAT_CHN_DATA_CHK |
              SCHN_STAT_CHN_CTRL_CHK | SCHN_STAT_INTF_CTRL_CHK)))
                return;
        CIO_MSG_EVENT(0, "Channel-Check or Interface-Control-Check "
                      "received"
                      " ... device %04x on subchannel 0.%x.%04x, dev_stat "
                      ": %02X sch_stat : %02X\n",
                      cdev->private->dev_id.devno, sch->schid.ssid,
                      sch->schid.sch_no,
                      scsw_dstat(&irb->scsw), scsw_cstat(&irb->scsw));
        sprintf(dbf_text, "chk%x", sch->schid.sch_no);
        CIO_TRACE_EVENT(0, dbf_text);
        CIO_HEX_EVENT(0, irb, sizeof(struct irb));
}

/*
 * Some paths became not operational (pno bit in scsw is set).
 */
static void
ccw_device_path_notoper(struct ccw_device *cdev)
{
        struct subchannel *sch;

        sch = to_subchannel(cdev->dev.parent);
        if (cio_update_schib(sch))
                goto doverify;

        CIO_MSG_EVENT(0, "%s(0.%x.%04x) - path(s) %02x are "
                      "not operational \n", __func__,
                      sch->schid.ssid, sch->schid.sch_no,
                      sch->schib.pmcw.pnom);

        sch->lpm &= ~sch->schib.pmcw.pnom;
doverify:
        cdev->private->flags.doverify = 1;
}

/*
 * Copy valid bits from the extended control word to device irb.
 */
static void
ccw_device_accumulate_ecw(struct ccw_device *cdev, struct irb *irb)
{
        /*
         * Copy extended control bit if it is valid... yes there
         * are condition that have to be met for the extended control
         * bit to have meaning. Sick.
         */
        cdev->private->dma_area->irb.scsw.cmd.ectl = 0;
        if ((irb->scsw.cmd.stctl & SCSW_STCTL_ALERT_STATUS) &&
            !(irb->scsw.cmd.stctl & SCSW_STCTL_INTER_STATUS))
                cdev->private->dma_area->irb.scsw.cmd.ectl = irb->scsw.cmd.ectl;
        /* Check if extended control word is valid. */
        if (!cdev->private->dma_area->irb.scsw.cmd.ectl)
                return;
        /* Copy concurrent sense / model dependent information. */
        memcpy(&cdev->private->dma_area->irb.ecw, irb->ecw, sizeof(irb->ecw));
}

/*
 * Check if extended status word is valid.
 */
static int
ccw_device_accumulate_esw_valid(struct irb *irb)
{
        if (!irb->scsw.cmd.eswf &&
            (irb->scsw.cmd.stctl == SCSW_STCTL_STATUS_PEND))
                return 0;
        if (irb->scsw.cmd.stctl ==
                        (SCSW_STCTL_INTER_STATUS|SCSW_STCTL_STATUS_PEND) &&
            !(irb->scsw.cmd.actl & SCSW_ACTL_SUSPENDED))
                return 0;
        return 1;
}

/*
 * Copy valid bits from the extended status word to device irb.
 */
static void
ccw_device_accumulate_esw(struct ccw_device *cdev, struct irb *irb)
{
        struct irb *cdev_irb;
        struct sublog *cdev_sublog, *sublog;

        if (!ccw_device_accumulate_esw_valid(irb))
                return;

        cdev_irb = &cdev->private->dma_area->irb;

        /* Copy last path used mask. */
        cdev_irb->esw.esw1.lpum = irb->esw.esw1.lpum;

        /* Copy subchannel logout information if esw is of format 0. */
        if (irb->scsw.cmd.eswf) {
                cdev_sublog = &cdev_irb->esw.esw0.sublog;
                sublog = &irb->esw.esw0.sublog;
                /* Copy extended status flags. */
                cdev_sublog->esf = sublog->esf;
                /*
                 * Copy fields that have a meaning for channel data check
                 * channel control check and interface control check.
                 */
                if (irb->scsw.cmd.cstat & (SCHN_STAT_CHN_DATA_CHK |
                                       SCHN_STAT_CHN_CTRL_CHK |
                                       SCHN_STAT_INTF_CTRL_CHK)) {
                        /* Copy ancillary report bit. */
                        cdev_sublog->arep = sublog->arep;
                        /* Copy field-validity-flags. */
                        cdev_sublog->fvf = sublog->fvf;
                        /* Copy storage access code. */
                        cdev_sublog->sacc = sublog->sacc;
                        /* Copy termination code. */
                        cdev_sublog->termc = sublog->termc;
                        /* Copy sequence code. */
                        cdev_sublog->seqc = sublog->seqc;
                }
                /* Copy device status check. */
                cdev_sublog->devsc = sublog->devsc;
                /* Copy secondary error. */
                cdev_sublog->serr = sublog->serr;
                /* Copy i/o-error alert. */
                cdev_sublog->ioerr = sublog->ioerr;
                /* Copy channel path timeout bit. */
                if (irb->scsw.cmd.cstat & SCHN_STAT_INTF_CTRL_CHK)
                        cdev_irb->esw.esw0.erw.cpt = irb->esw.esw0.erw.cpt;
                /* Copy failing storage address validity flag. */
                cdev_irb->esw.esw0.erw.fsavf = irb->esw.esw0.erw.fsavf;
                if (cdev_irb->esw.esw0.erw.fsavf) {
                        /* ... and copy the failing storage address. */
                        memcpy(cdev_irb->esw.esw0.faddr, irb->esw.esw0.faddr,
                               sizeof (irb->esw.esw0.faddr));
                        /* ... and copy the failing storage address format. */
                        cdev_irb->esw.esw0.erw.fsaf = irb->esw.esw0.erw.fsaf;
                }
                /* Copy secondary ccw address validity bit. */
                cdev_irb->esw.esw0.erw.scavf = irb->esw.esw0.erw.scavf;
                if (irb->esw.esw0.erw.scavf)
                        /* ... and copy the secondary ccw address. */
                        cdev_irb->esw.esw0.saddr = irb->esw.esw0.saddr;
                
        }
        /* FIXME: DCTI for format 2? */

        /* Copy authorization bit. */
        cdev_irb->esw.esw0.erw.auth = irb->esw.esw0.erw.auth;
        /* Copy path verification required flag. */
        cdev_irb->esw.esw0.erw.pvrf = irb->esw.esw0.erw.pvrf;
        if (irb->esw.esw0.erw.pvrf)
                cdev->private->flags.doverify = 1;
        /* Copy concurrent sense bit. */
        cdev_irb->esw.esw0.erw.cons = irb->esw.esw0.erw.cons;
        if (irb->esw.esw0.erw.cons)
                cdev_irb->esw.esw0.erw.scnt = irb->esw.esw0.erw.scnt;
}

/*
 * Accumulate status from irb to devstat.
 */
void
ccw_device_accumulate_irb(struct ccw_device *cdev, struct irb *irb)
{
        struct irb *cdev_irb;

        /*
         * Check if the status pending bit is set in stctl.
         * If not, the remaining bit have no meaning and we must ignore them.
         * The esw is not meaningful as well...
         */
        if (!(scsw_stctl(&irb->scsw) & SCSW_STCTL_STATUS_PEND))
                return;

        /* Check for channel checks and interface control checks. */
        ccw_device_msg_control_check(cdev, irb);

        /* Check for path not operational. */
        if (scsw_is_valid_pno(&irb->scsw) && scsw_pno(&irb->scsw))
                ccw_device_path_notoper(cdev);
        /* No irb accumulation for transport mode irbs. */
        if (scsw_is_tm(&irb->scsw)) {
                memcpy(&cdev->private->dma_area->irb, irb, sizeof(struct irb));
                return;
        }
        /*
         * Don't accumulate unsolicited interrupts.
         */
        if (!scsw_is_solicited(&irb->scsw))
                return;

        cdev_irb = &cdev->private->dma_area->irb;

        /*
         * If the clear function had been performed, all formerly pending
         * status at the subchannel has been cleared and we must not pass
         * intermediate accumulated status to the device driver.
         */
        if (irb->scsw.cmd.fctl & SCSW_FCTL_CLEAR_FUNC)
                memset(&cdev->private->dma_area->irb, 0, sizeof(struct irb));

        /* Copy bits which are valid only for the start function. */
        if (irb->scsw.cmd.fctl & SCSW_FCTL_START_FUNC) {
                /* Copy key. */
                cdev_irb->scsw.cmd.key = irb->scsw.cmd.key;
                /* Copy suspend control bit. */
                cdev_irb->scsw.cmd.sctl = irb->scsw.cmd.sctl;
                /* Accumulate deferred condition code. */
                cdev_irb->scsw.cmd.cc |= irb->scsw.cmd.cc;
                /* Copy ccw format bit. */
                cdev_irb->scsw.cmd.fmt = irb->scsw.cmd.fmt;
                /* Copy prefetch bit. */
                cdev_irb->scsw.cmd.pfch = irb->scsw.cmd.pfch;
                /* Copy initial-status-interruption-control. */
                cdev_irb->scsw.cmd.isic = irb->scsw.cmd.isic;
                /* Copy address limit checking control. */
                cdev_irb->scsw.cmd.alcc = irb->scsw.cmd.alcc;
                /* Copy suppress suspend bit. */
                cdev_irb->scsw.cmd.ssi = irb->scsw.cmd.ssi;
        }

        /* Take care of the extended control bit and extended control word. */
        ccw_device_accumulate_ecw(cdev, irb);
            
        /* Accumulate function control. */
        cdev_irb->scsw.cmd.fctl |= irb->scsw.cmd.fctl;
        /* Copy activity control. */
        cdev_irb->scsw.cmd.actl = irb->scsw.cmd.actl;
        /* Accumulate status control. */
        cdev_irb->scsw.cmd.stctl |= irb->scsw.cmd.stctl;
        /*
         * Copy ccw address if it is valid. This is a bit simplified
         * but should be close enough for all practical purposes.
         */
        if ((irb->scsw.cmd.stctl & SCSW_STCTL_PRIM_STATUS) ||
            ((irb->scsw.cmd.stctl ==
              (SCSW_STCTL_INTER_STATUS|SCSW_STCTL_STATUS_PEND)) &&
             (irb->scsw.cmd.actl & SCSW_ACTL_DEVACT) &&
             (irb->scsw.cmd.actl & SCSW_ACTL_SCHACT)) ||
            (irb->scsw.cmd.actl & SCSW_ACTL_SUSPENDED))
                cdev_irb->scsw.cmd.cpa = irb->scsw.cmd.cpa;
        /* Accumulate device status, but not the device busy flag. */
        cdev_irb->scsw.cmd.dstat &= ~DEV_STAT_BUSY;
        /* dstat is not always valid. */
        if (irb->scsw.cmd.stctl &
            (SCSW_STCTL_PRIM_STATUS | SCSW_STCTL_SEC_STATUS
             | SCSW_STCTL_INTER_STATUS | SCSW_STCTL_ALERT_STATUS))
                cdev_irb->scsw.cmd.dstat |= irb->scsw.cmd.dstat;
        /* Accumulate subchannel status. */
        cdev_irb->scsw.cmd.cstat |= irb->scsw.cmd.cstat;
        /* Copy residual count if it is valid. */
        if ((irb->scsw.cmd.stctl & SCSW_STCTL_PRIM_STATUS) &&
            (irb->scsw.cmd.cstat & ~(SCHN_STAT_PCI | SCHN_STAT_INCORR_LEN))
             == 0)
                cdev_irb->scsw.cmd.count = irb->scsw.cmd.count;

        /* Take care of bits in the extended status word. */
        ccw_device_accumulate_esw(cdev, irb);

        /*
         * Check whether we must issue a SENSE CCW ourselves if there is no
         * concurrent sense facility installed for the subchannel.
         * No sense is required if no delayed sense is pending
         * and we did not get a unit check without sense information.
         *
         * Note: We should check for ioinfo[irq]->flags.consns but VM
         *       violates the ESA/390 architecture and doesn't present an
         *       operand exception for virtual devices without concurrent
         *       sense facility available/supported when enabling the
         *       concurrent sense facility.
         */
        if ((cdev_irb->scsw.cmd.dstat & DEV_STAT_UNIT_CHECK) &&
            !(cdev_irb->esw.esw0.erw.cons))
                cdev->private->flags.dosense = 1;
}

/*
 * Do a basic sense.
 */
int
ccw_device_do_sense(struct ccw_device *cdev, struct irb *irb)
{
        struct subchannel *sch;
        struct ccw1 *sense_ccw;
        int rc;

        sch = to_subchannel(cdev->dev.parent);

        /* A sense is required, can we do it now ? */
        if (scsw_actl(&irb->scsw) & (SCSW_ACTL_DEVACT | SCSW_ACTL_SCHACT))
                /*
                 * we received an Unit Check but we have no final
                 *  status yet, therefore we must delay the SENSE
                 *  processing. We must not report this intermediate
                 *  status to the device interrupt handler.
                 */
                return -EBUSY;

        /*
         * We have ending status but no sense information. Do a basic sense.
         */
        sense_ccw = &to_io_private(sch)->dma_area->sense_ccw;
        sense_ccw->cmd_code = CCW_CMD_BASIC_SENSE;
        sense_ccw->cda = (__u32) __pa(cdev->private->dma_area->irb.ecw);
        sense_ccw->count = SENSE_MAX_COUNT;
        sense_ccw->flags = CCW_FLAG_SLI;

        rc = cio_start(sch, sense_ccw, 0xff);
        if (rc == -ENODEV || rc == -EACCES)
                dev_fsm_event(cdev, DEV_EVENT_VERIFY);
        return rc;
}

/*
 * Add information from basic sense to devstat.
 */
void
ccw_device_accumulate_basic_sense(struct ccw_device *cdev, struct irb *irb)
{
        /*
         * Check if the status pending bit is set in stctl.
         * If not, the remaining bit have no meaning and we must ignore them.
         * The esw is not meaningful as well...
         */
        if (!(scsw_stctl(&irb->scsw) & SCSW_STCTL_STATUS_PEND))
                return;

        /* Check for channel checks and interface control checks. */
        ccw_device_msg_control_check(cdev, irb);

        /* Check for path not operational. */
        if (scsw_is_valid_pno(&irb->scsw) && scsw_pno(&irb->scsw))
                ccw_device_path_notoper(cdev);

        if (!(irb->scsw.cmd.dstat & DEV_STAT_UNIT_CHECK) &&
            (irb->scsw.cmd.dstat & DEV_STAT_CHN_END)) {
                cdev->private->dma_area->irb.esw.esw0.erw.cons = 1;
                cdev->private->flags.dosense = 0;
        }
        /* Check if path verification is required. */
        if (ccw_device_accumulate_esw_valid(irb) &&
            irb->esw.esw0.erw.pvrf)
                cdev->private->flags.doverify = 1;
}

/*
 * This function accumulates the status into the private devstat and
 * starts a basic sense if one is needed.
 */
int
ccw_device_accumulate_and_sense(struct ccw_device *cdev, struct irb *irb)
{
        ccw_device_accumulate_irb(cdev, irb);
        if ((irb->scsw.cmd.actl  & (SCSW_ACTL_DEVACT | SCSW_ACTL_SCHACT)) != 0)
                return -EBUSY;
        /* Check for basic sense. */
        if (cdev->private->flags.dosense &&
            !(irb->scsw.cmd.dstat & DEV_STAT_UNIT_CHECK)) {
                cdev->private->dma_area->irb.esw.esw0.erw.cons = 1;
                cdev->private->flags.dosense = 0;
                return 0;
        }
        if (cdev->private->flags.dosense) {
                ccw_device_do_sense(cdev, irb);
                return -EBUSY;
        }
        return 0;
}